implement on model update callback

lib/goo/base/resource.rb

@@ -298,26 +298,45 @@ def add_aggregate(attribute,aggregate,value)
       def save(*opts)
 
         if self.kind_of?(Goo::Base::Enum)
-          unless opts[0] && opts[0][:init_enum]
-            raise ArgumentError, "Enums can only be created on initialization"
-          end
+          raise ArgumentError, "Enums can only be created on initialization" unless opts[0] && opts[0][:init_enum]
         end
         batch_file = nil
-        if opts && opts.length > 0
-          if opts.first.is_a?(Hash) && opts.first[:batch] && opts.first[:batch].is_a?(File)
+        callbacks = true
+        if opts && opts.length > 0 && opts.first.is_a?(Hash)
+          if opts.first[:batch] && opts.first[:batch].is_a?(File)
             batch_file = opts.first[:batch]
           end
+
+          callbacks = opts.first[:callbacks]
         end
 
         if !batch_file
-          if not modified?
-            return self
-          end
+          return self if not modified?
           raise Goo::Base::NotValidException, "Object is not valid. Check errors." unless valid?
         end
 
+        #set default values before saving
+        unless self.persistent?
+          self.class.attributes_with_defaults.each do |attr|
+            value = self.send("#{attr}")
+            if value.nil?
+              value = self.class.default(attr).call(self)
+              self.send("#{attr}=", value)
+            end
+          end
+        end
+
+        #call update callback before saving
+        if callbacks
+          self.class.attributes_with_update_callbacks.each do |attr|
+            Goo::Validators::Enforce.enforce_callbacks(self, attr)
+          end
+        end
+
         graph_insert, graph_delete = Goo::SPARQL::Triples.model_update_triples(self)
-        graph = self.graph()
+        graph = self.graph
+
+
         if graph_delete and graph_delete.size > 0
           begin
             Goo.sparql_update_client.delete_data(graph_delete, graph: graph)

lib/goo/base/settings/settings.rb

@@ -96,6 +96,16 @@ def attributes_with_defaults
                   select{ |attr,opts| opts[:default] }).keys()
         end
 
+        def attributes_with_update_callbacks
+           (@model_settings[:attributes].
+            select{ |attr,opts| opts[:onUpdate] }).keys
+        end
+
+
+        def update_callbacks(attr)
+          @model_settings[:attributes][attr][:onUpdate]
+        end
+
         def default(attr)
           return @model_settings[:attributes][attr][:default]
         end

test/test_update_callbacks.rb

@@ -0,0 +1,53 @@
+require_relative 'test_case'
+
+
+require_relative 'models'
+
+class TestUpdateCallBack < Goo::Base::Resource
+  model :update_callback_model, name_with: :code
+  attribute :code, enforce: [:string, :existence]
+  attribute :name, enforce: [:string, :existence]
+  attribute :first_name, onUpdate: :update_name
+  attribute :last_name, onUpdate: :update_name
+
+
+  def update_name(inst, attr)
+    self.name = self.first_name + self.last_name
+  end
+end
+
+class TestUpdateCallBacks < MiniTest::Unit::TestCase
+
+  def self.before_suite
+    GooTestData.delete_all [TestUpdateCallBack]
+  end
+
+  def self.after_suite
+    GooTestData.delete_all [TestUpdateCallBack]
+  end
+
+
+  def test_update_callback
+    p = TestUpdateCallBack.new
+    p.code = "1"
+    p.name = "name"
+    p.first_name = "first_name"
+    p.last_name = "last_name"
+
+    assert p.valid?
+    p.save
+
+    p.bring_remaining
+
+    assert_equal p.first_name + p.last_name, p.name
+
+    p.last_name = "last_name2"
+    p.save
+
+    p.bring_remaining
+    assert_equal  "last_name2",  p.last_name
+    assert_equal p.first_name + p.last_name, p.name
+  end
+
+end
+